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</h1><!--]--><!--]--><!--]--></div></div><div class="content" data-v-4fe9b7bd><!--[--><!--]--><main data-v-4fe9b7bd><div style="position:relative;" class="vt-doc nodejs" data-v-4fe9b7bd><div><h1 id="_06-【nodejs内置模块（中）】" tabindex="-1">06 【nodejs内置模块（中）】 <a class="header-anchor" href="#_06-【nodejs内置模块（中）】" aria-hidden="true">#</a></h1><h2 id="_1-路劲处理模块-path" tabindex="-1">1.路劲处理模块 path <a class="header-anchor" href="#_1-路劲处理模块-path" aria-hidden="true">#</a></h2><h3 id="_1-1-模块概览" tabindex="-1">1.1 模块概览 <a class="header-anchor" href="#_1-1-模块概览" aria-hidden="true">#</a></h3><p>在nodejs中，path是个使用频率很高，但却让人又爱又恨的模块。部分因为文档说的不够清晰，部分因为接口的平台差异性。</p><p>将path的接口按照用途归类，仔细琢磨琢磨，也就没那么费解了。</p><h3 id="_1-2-获取路径-文件名-扩展名" tabindex="-1">1.2 获取路径/文件名/扩展名 <a class="header-anchor" href="#_1-2-获取路径-文件名-扩展名" aria-hidden="true">#</a></h3><ul><li>获取路径：path.dirname(filepath)</li><li>获取文件名：path.basename(filepath)</li><li>获取扩展名：path.extname(filepath)</li></ul><h4 id="_1-2-1-获取所在路径" tabindex="-1">1.2.1 获取所在路径 <a class="header-anchor" href="#_1-2-1-获取所在路径" aria-hidden="true">#</a></h4><p>例子如下：</p><div class="language-javascript line-numbers-mode"><pre><code><span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> path </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">require</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">path</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> filepath </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">/tmp/demo/js/test.js</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// 输出：/tmp/demo/js</span></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">( path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">dirname</span><span style="color:#A6ACCD;">(filepath) )</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br></div></div><h4 id="_1-2-2-获取文件名" tabindex="-1">1.2.2 获取文件名 <a class="header-anchor" href="#_1-2-2-获取文件名" aria-hidden="true">#</a></h4><p>严格意义上来说，path.basename(filepath) 只是输出路径的最后一部分，并不会判断是否文件名。</p><p>但大部分时候，我们可以用它来作为简易的“获取文件名“的方法。</p><div class="language-javascript line-numbers-mode"><pre><code><span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> path </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">require</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">path</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// 输出：test.js</span></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">( path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">basename</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">/tmp/demo/js/test.js</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">) )</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// 输出：test</span></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">( path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">basename</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">/tmp/demo/js/test/</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">) )</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// 输出：test</span></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">( path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">basename</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">/tmp/demo/js/test</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">) )</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br></div></div><p>如果只想获取文件名，单不包括文件扩展呢？可以用上第二个参数。</p><div class="language-javascript line-numbers-mode"><pre><code><span class="line"><span style="color:#676E95;font-style:italic;">// 输出：test</span></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">( path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">basename</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">/tmp/demo/js/test.js</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">.js</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">) )</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br></div></div><h4 id="_1-2-3-获取文件扩展名" tabindex="-1">1.2.3 获取文件扩展名 <a class="header-anchor" href="#_1-2-3-获取文件扩展名" aria-hidden="true">#</a></h4><p>简单的例子如下：</p><div class="language-javascript line-numbers-mode"><pre><code><span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> path </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">require</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">path</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> filepath </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">/tmp/demo/js/test.js</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// 输出：.js</span></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">( path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">extname</span><span style="color:#A6ACCD;">(filepath) )</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br></div></div><p>更详细的规则是如下：（假设 path.basename(filepath) === B ）</p><ul><li>从B的最后一个<code>.</code>开始截取，直到最后一个字符。</li><li>如果B中不存在<code>.</code>，或者B的第一个字符就是<code>.</code>，那么返回空字符串。</li></ul><p>直接看<a href="https://nodejs.org/api/path.html#path_path_extname_path" target="_blank" rel="noopener noreferrer">官方文档</a>的例子</p><div class="language-javascript line-numbers-mode"><pre><code><span class="line"><span style="color:#A6ACCD;">path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">extname</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">index.html</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// returns &#39;.html&#39;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#A6ACCD;">path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">extname</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">index.coffee.md</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// returns &#39;.md&#39;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#A6ACCD;">path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">extname</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">index.</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// returns &#39;.&#39;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#A6ACCD;">path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">extname</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">index</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// returns &#39;&#39;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#A6ACCD;">path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">extname</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">.index</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// returns &#39;&#39;</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br></div></div><h3 id="_1-3-路径组合" tabindex="-1">1.3 路径组合 <a class="header-anchor" href="#_1-3-路径组合" aria-hidden="true">#</a></h3><ul><li>path.join([...paths])</li><li>path.resolve([...paths])</li></ul><h4 id="_1-3-1-path-resolve-生成完成的绝对路径" tabindex="-1">1.3.1 path.resolve() 生成完成的绝对路径 <a class="header-anchor" href="#_1-3-1-path-resolve-生成完成的绝对路径" aria-hidden="true">#</a></h4><p>语法格式：</p><div class="language-js line-numbers-mode"><pre><code><span class="line"><span style="color:#A6ACCD;">path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">resolve</span><span style="color:#A6ACCD;">([</span><span style="color:#89DDFF;">...</span><span style="color:#A6ACCD;">myPaths])</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>解释：</p><ul><li>将路径或路径片段的序列解析为绝对路径。</li><li>返回的路径是<strong>从右往左</strong>处理，后面的每个 myPath 被依次解析，直到构造出一个完整的绝对路径。</li></ul><blockquote><p>你可以想象现在你在shell下面，从左到右运行一遍<code>cd path</code>命令，最终获取的绝对路径/文件名，就是这个接口所返回的结果了。</p></blockquote><p>代码举例：</p><div class="language-js line-numbers-mode"><pre><code><span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> path </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">require</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">path</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">let</span><span style="color:#A6ACCD;"> arr1 </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> [</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">/foo1/foo2</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">dselegent</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">foo3</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">]</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#C792EA;">let</span><span style="color:#A6ACCD;"> result1 </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">resolve</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">...</span><span style="color:#A6ACCD;">arr1)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">(result1)</span><span style="color:#89DDFF;">;</span><span style="color:#A6ACCD;"> </span><span style="color:#676E95;font-style:italic;">// 打印结果：/foo1/foo2/dselegent/foo3</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">let</span><span style="color:#A6ACCD;"> arr2 </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> [</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">/foo1/foo2</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">/dselegent</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">foo3</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">]</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#C792EA;">let</span><span style="color:#A6ACCD;"> result2 </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">resolve</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">...</span><span style="color:#A6ACCD;">arr2)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">(result2)</span><span style="color:#89DDFF;">;</span><span style="color:#A6ACCD;"> </span><span style="color:#676E95;font-style:italic;">// 打印结果：/dselegent/foo3</span></span>
<span class="line"></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br></div></div><div class="language-javascript line-numbers-mode"><pre><code><span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> path </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">require</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">path</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// 假设当前工作路径是 /Users/a/Documents/git-code/nodejs-learning-guide/examples/2016.11.08-node-path</span></span>
<span class="line"></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// 输出 /Users/a/Documents/git-code/nodejs-learning-guide/examples/2016.11.08-node-path</span></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">( path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">resolve</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;&#39;</span><span style="color:#A6ACCD;">) )</span></span>
<span class="line"></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// 输出 /Users/a/Documents/git-code/nodejs-learning-guide/examples/2016.11.08-node-path</span></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">( path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">resolve</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">.</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">) )</span></span>
<span class="line"></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// 输出 /foo/bar/baz</span></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">( path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">resolve</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">/foo/bar</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./baz</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">) )</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// 输出 /foo/bar/baz</span></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">( path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">resolve</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">/foo/bar</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./baz/</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">) )</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// 输出 /tmp/file</span></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">( path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">resolve</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">/foo/bar</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">/tmp/file/</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">) )</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// 输出 /Users/a/Documents/git-code/nodejs-learning-guide/examples/2016.11.08-node-path/www/js/mod.js</span></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">( path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">resolve</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">www</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">js/upload</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">../mod.js</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">) )</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br><span class="line-number">19</span><br><span class="line-number">20</span><br><span class="line-number">21</span><br></div></div><h4 id="_1-3-2-path-join-将多个路径进行拼接" tabindex="-1">1.3.2 path.join() 将多个路径进行拼接 <a class="header-anchor" href="#_1-3-2-path-join-将多个路径进行拼接" aria-hidden="true">#</a></h4><p>如果是我们手动拼接路径，容易出错。这个时候，可以利用 path.join() 方法将路径进行拼接。</p><p>语法格式：</p><div class="language-js line-numbers-mode"><pre><code><span class="line"><span style="color:#A6ACCD;">path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">join</span><span style="color:#A6ACCD;">([</span><span style="color:#89DDFF;">...</span><span style="color:#A6ACCD;">paths])</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br></div></div><p>解释：使用平台特定的分隔符作为定界符将所有给定的 path 片段连接在一起，然后规范化生成的路径。</p><p>代码举例：</p><div class="language-js line-numbers-mode"><pre><code><span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> path </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">require</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">path</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> result1 </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">join</span><span style="color:#A6ACCD;">(__dirname</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./app.js</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">(result1)</span><span style="color:#89DDFF;">;</span><span style="color:#A6ACCD;"> </span><span style="color:#676E95;font-style:italic;">// 返回：/Users/smyhvae/dselegent/app.js</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> result2 </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">join</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">/foo1</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">foo2</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./foo3</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">(result2)</span><span style="color:#89DDFF;">;</span><span style="color:#A6ACCD;"> </span><span style="color:#676E95;font-style:italic;">// 返回：/foo1/foo2/foo3</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> result3 </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">join</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">/foo1</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">foo2</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">/foo3</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">(result3)</span><span style="color:#89DDFF;">;</span><span style="color:#A6ACCD;"> </span><span style="color:#676E95;font-style:italic;">// 返回：/foo1/foo2/foo3</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br></div></div><h4 id="_1-3-3-path-resolve-和-path-join-区别" tabindex="-1">1.3.3 path.resolve 和 path.join 区别 <a class="header-anchor" href="#_1-3-3-path-resolve-和-path-join-区别" aria-hidden="true">#</a></h4><p>path.resolve 和 path.join 都是属于 path 核心模块下的方法，用来拼接路径。</p><p>都可以拼接成一个完整路径.</p><div class="language-js line-numbers-mode"><pre><code><span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> path </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">require</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&quot;</span><span style="color:#C3E88D;">path</span><span style="color:#89DDFF;">&quot;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> dirname </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">/User/Desktop</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> basename </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">abc.txt</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#A6ACCD;">path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">join</span><span style="color:#A6ACCD;">(dirname</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> basename)</span><span style="color:#89DDFF;">;</span><span style="color:#A6ACCD;">  </span><span style="color:#676E95;font-style:italic;">// /User/Desktop/abc.txt</span></span>
<span class="line"></span>
<span class="line"><span style="color:#A6ACCD;">path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">resolve</span><span style="color:#A6ACCD;">(dirname</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> basename)</span><span style="color:#89DDFF;">;</span><span style="color:#A6ACCD;">  </span><span style="color:#676E95;font-style:italic;">// /User/Desktop/abc.txt</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br></div></div><p>如果 dirname 是以 ./ 、../、不加 / 开头的话，那么 resolve 会找到磁盘下的根目录</p><div class="language-javascript line-numbers-mode"><pre><code><span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> path </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">require</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&quot;</span><span style="color:#C3E88D;">path</span><span style="color:#89DDFF;">&quot;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span></span>
<span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> dirname </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">../User/Desktop</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> basename </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">abc.txt</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span></span>
<span class="line"><span style="color:#A6ACCD;">path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">join</span><span style="color:#A6ACCD;">(dirname</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> basename)</span><span style="color:#89DDFF;">;</span><span style="color:#A6ACCD;">  </span><span style="color:#676E95;font-style:italic;">// ../User/Desktop/abc.txt</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span></span>
<span class="line"><span style="color:#A6ACCD;">path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">resolve</span><span style="color:#A6ACCD;">(dirname</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> basename)</span><span style="color:#89DDFF;">;</span><span style="color:#A6ACCD;">  </span><span style="color:#676E95;font-style:italic;">// /Users/Desktop/node/User/Desktop/abc.txt</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br></div></div><p>如果 basename 是以 / 开头的，那么 resolve 就会直接返回 basename</p><div class="language-javascript line-numbers-mode"><pre><code><span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> path </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">require</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&quot;</span><span style="color:#C3E88D;">path</span><span style="color:#89DDFF;">&quot;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span></span>
<span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> dirname </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">/User/Desktop</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> basename </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">/abc.txt</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span></span>
<span class="line"><span style="color:#A6ACCD;">path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">join</span><span style="color:#A6ACCD;">(dirname</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> basename)</span><span style="color:#89DDFF;">;</span><span style="color:#A6ACCD;">  </span><span style="color:#676E95;font-style:italic;">// /User/Desktop/abc.txt</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span></span>
<span class="line"><span style="color:#A6ACCD;">path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">resolve</span><span style="color:#A6ACCD;">(dirname</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> basename)</span><span style="color:#89DDFF;">;</span><span style="color:#A6ACCD;">  </span><span style="color:#676E95;font-style:italic;">// /abc.txt</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br></div></div><h3 id="_1-4-几个常见路径" tabindex="-1">1.4 几个常见路径 <a class="header-anchor" href="#_1-4-几个常见路径" aria-hidden="true">#</a></h3><ul><li><code>__dirname</code>：这是一个常量，表示：当前执行文件所在<strong>完整目录</strong>。</li><li><code>__filename</code>：这是一个常量。表示：当前执行文件的<strong>完整目录 + 文件名</strong>。</li><li><code>process.cwd</code>：获取当前执行 Node命令 时的目录名。</li></ul><p>代码举例：</p><div class="language-js line-numbers-mode"><pre><code><span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">(__dirname)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">(__filename)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">(process</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">cwd</span><span style="color:#A6ACCD;">())</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br></div></div><p>运行结果：</p><div class="language-bash line-numbers-mode"><pre><code><span class="line"><span style="color:#A6ACCD;">$ node app.js</span></span>
<span class="line"></span>
<span class="line"><span style="color:#A6ACCD;">/Users/smyhvae/dselegent</span></span>
<span class="line"><span style="color:#A6ACCD;">/Users/smyhvae/dselegent/app.js</span></span>
<span class="line"><span style="color:#A6ACCD;">/Users/smyhvae/dselegent</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br></div></div><h2 id="_2-本地文件操作模块-fs" tabindex="-1">2.本地文件操作模块 fs <a class="header-anchor" href="#_2-本地文件操作模块-fs" aria-hidden="true">#</a></h2><blockquote><h3 id="node-js-中的同步和异步的区别" tabindex="-1">Node.js 中的同步和异步的区别 <a class="header-anchor" href="#node-js-中的同步和异步的区别" aria-hidden="true">#</a></h3><p>fs模块对文件的几乎所有操作都有同步和异步两种形式。例如：readFile() 和 readFileSync()。</p><p>区别：</p><ul><li>同步调用会阻塞代码的执行，异步则不会。</li><li>异步调用会将 读取任务 下达到任务队列，直到任务执行完成才会回调。</li><li>异常处理方面：同步必须使用 try catch 方式，异步可以通过回调函数的第一个参数。【重要】</li></ul></blockquote><h3 id="_2-1-文件读取" tabindex="-1">2.1 文件读取 <a class="header-anchor" href="#_2-1-文件读取" aria-hidden="true">#</a></h3><p><strong>同步读取</strong></p><div class="language-javascript line-numbers-mode"><pre><code><span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> fs </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">require</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fs</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> data</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">try</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">data</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">fs</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">readFileSync</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./fileForRead.txt</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">utf8</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">文件内容: </span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">+</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">data</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#89DDFF;font-style:italic;">catch</span><span style="color:#A6ACCD;">(err)</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">error</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">读取文件出错: </span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">+</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">err</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">message</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br></div></div><p>输出如下：</p><div class="language-bash line-numbers-mode"><pre><code><span class="line"><span style="color:#A6ACCD;">/usr/local/bin/node readFileSync.js</span></span>
<span class="line"><span style="color:#A6ACCD;">文件内容: hello world</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br></div></div><p><strong>异步读取</strong></p><div class="language-javascript line-numbers-mode"><pre><code><span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> fs </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">require</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fs</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#A6ACCD;">fs</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">readFile</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./fileForRead.txt</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">utf8</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">function</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;">err</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> data</span><span style="color:#89DDFF;">){</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#89DDFF;font-style:italic;">if</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">err</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">        </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">error</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">读取文件出错: </span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">+</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">err</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">message</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">文件内容: </span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">+</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">data</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br></div></div><p>输出如下</p><div class="language-bash line-numbers-mode"><pre><code><span class="line"><span style="color:#A6ACCD;">/usr/local/bin/node readFile.js</span></span>
<span class="line"><span style="color:#A6ACCD;">文件内容: hello world</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br></div></div><blockquote><p><strong>fs/promises 从 Node.js 14 开始可用</strong> 从 Node.js 14 开始，fs 模块提供了两种使用基于 promises 的文件系统的方法。这些 promises 可以通过 <code>require(&#39;fs&#39;).promises</code> 或 <code>require(&#39;fs/promises&#39;) </code>获得。</p></blockquote><div class="language-js line-numbers-mode"><pre><code><span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">readFile</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fs/promises</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">try</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#C792EA;">const</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">contents</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">await</span><span style="color:#F07178;"> </span><span style="color:#82AAFF;">readFile</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">filePath</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> encoding</span><span style="color:#89DDFF;">:</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">utf8</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">contents</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">catch</span><span style="color:#A6ACCD;"> (err) </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">error</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">err</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">message</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br></div></div><h3 id="_2-2-文件写入" tabindex="-1">2.2 文件写入 <a class="header-anchor" href="#_2-2-文件写入" aria-hidden="true">#</a></h3><p>备注：以下代码，如果文件不存在，则创建文件；如果文件存在，则覆盖文件内容；</p><p><strong>异步写入</strong></p><div class="language-javascript line-numbers-mode"><pre><code><span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> fs </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">require</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fs</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#A6ACCD;">fs</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">writeFile</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./fileForWrite.txt</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">hello world</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">utf8</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">function</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;">err</span><span style="color:#89DDFF;">){</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#89DDFF;font-style:italic;">if</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">err</span><span style="color:#F07178;">) </span><span style="color:#89DDFF;font-style:italic;">throw</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">err</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">文件写入成功</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br></div></div><p><strong>同步写入</strong></p><div class="language-javascript line-numbers-mode"><pre><code><span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> fs </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">require</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fs</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">try</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">fs</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">writeFileSync</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./fileForWrite1.txt</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">hello world</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">utf8</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">文件写入成功</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#89DDFF;font-style:italic;">catch</span><span style="color:#A6ACCD;">(err)</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#89DDFF;font-style:italic;">throw</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">err</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br></div></div><p><strong>promises</strong></p><div class="language-js line-numbers-mode"><pre><code><span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">writeFile</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fs/promises</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">try</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#C792EA;">const</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">contents</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">await</span><span style="color:#F07178;"> </span><span style="color:#82AAFF;">writeFile</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">message.txt</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">hello world</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> encoding</span><span style="color:#89DDFF;">:</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">utf8</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">contents</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">catch</span><span style="color:#A6ACCD;"> (err) </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#89DDFF;">  </span><span style="color:#676E95;font-style:italic;">// When a request is aborted - err is an AbortError</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">error</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">err</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br></div></div><h3 id="_2-3-文件是否存在" tabindex="-1">2.3 文件是否存在 <a class="header-anchor" href="#_2-3-文件是否存在" aria-hidden="true">#</a></h3><p><code>fs.exists()</code>已经是<code>deprecated</code>状态，现在可以通过下面代码判断文件是否存在。</p><p><strong>异步本</strong></p><div class="language-js line-numbers-mode"><pre><code><span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> fs </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">require</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fs</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#676E95;font-style:italic;">//检查文件是否存在于当前目录中</span></span>
<span class="line"><span style="color:#A6ACCD;">fs</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">access</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">package.json</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> fs</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">constants</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">F_OK</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> err </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#89DDFF;font-style:italic;">if</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">err</span><span style="color:#F07178;">) </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">        </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">package.json不存在于当前目录中</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;">        </span><span style="color:#89DDFF;font-style:italic;">return</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">package.json存在于当前目录中</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#A6ACCD;">fs</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">access</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">index.js</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> fs</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">constants</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">F_OK</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> err </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#89DDFF;font-style:italic;">if</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">err</span><span style="color:#F07178;">) </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">        </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">index.js不存在于当前目录中</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;">        </span><span style="color:#89DDFF;font-style:italic;">return</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">index.js存在于当前目录中</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br></div></div><p><code>fs.access()</code>除了判断文件是否存在（默认模式），还可以用来判断文件的权限。</p><p>备忘：<code>fs.constants.F_OK</code>等常量无法获取（node v6.1，mac 10.11.4下，<code>fs.constants</code>是<code>undefined</code>）</p><p><strong>同步</strong></p><div class="language-js line-numbers-mode"><pre><code><span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">accessSync</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">constants</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fs</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">try</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#82AAFF;">accessSync</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">etc/passwd</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">constants</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">R_OK</span><span style="color:#F07178;"> )</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">can read</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">catch</span><span style="color:#A6ACCD;"> (err) </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">error</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">no access!</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br></div></div><p><strong>promises</strong></p><div class="language-js line-numbers-mode"><pre><code><span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">access</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">constants</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">node:fs/promises</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">try</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#89DDFF;font-style:italic;">await</span><span style="color:#F07178;"> </span><span style="color:#82AAFF;">access</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">/etc/passwd</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">constants</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">R_OK</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">can access</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">catch</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">error</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">cannot access</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br></div></div><h3 id="_2-4-删除文件" tabindex="-1">2.4 删除文件 <a class="header-anchor" href="#_2-4-删除文件" aria-hidden="true">#</a></h3><p><strong>异步版本</strong></p><div class="language-javascript line-numbers-mode"><pre><code><span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> fs </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">require</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fs</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#A6ACCD;">fs</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">unlink</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./fileForUnlink.txt</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">function</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;">err</span><span style="color:#89DDFF;">){</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#89DDFF;font-style:italic;">if</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">err</span><span style="color:#F07178;">) </span><span style="color:#89DDFF;font-style:italic;">throw</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">err</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">文件删除成功</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br></div></div><p><strong>同步版本</strong></p><div class="language-js line-numbers-mode"><pre><code><span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">unlinkSync</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fs</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">try</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#82AAFF;">unlinkSync</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">/tmp/hello</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">successfully deleted /tmp/hello</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">catch</span><span style="color:#A6ACCD;"> (err) </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#89DDFF;">  </span><span style="color:#676E95;font-style:italic;">// handle the error</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br></div></div><p><strong>promises</strong></p><div class="language-js line-numbers-mode"><pre><code><span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">unlink</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fs/promises</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">try</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#89DDFF;font-style:italic;">await</span><span style="color:#F07178;"> </span><span style="color:#82AAFF;">unlink</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">/tmp/hello</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">successfully deleted /tmp/hello</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">catch</span><span style="color:#A6ACCD;"> (err) </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#89DDFF;">  </span><span style="color:#676E95;font-style:italic;">// handle the error</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br></div></div><h3 id="_2-5-创建目录" tabindex="-1">2.5 创建目录 <a class="header-anchor" href="#_2-5-创建目录" aria-hidden="true">#</a></h3><p><strong>异步版本</strong>（如果目录已存在，会报错）</p><div class="language-javascript line-numbers-mode"><pre><code><span class="line"><span style="color:#676E95;font-style:italic;">// fs.mkdir(path[, mode], callback)</span></span>
<span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> fs </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">require</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fs</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#A6ACCD;">fs</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">mkdir</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">sub</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">function</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;">err</span><span style="color:#89DDFF;">){</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#89DDFF;font-style:italic;">if</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">err</span><span style="color:#F07178;">) </span><span style="color:#89DDFF;font-style:italic;">throw</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">err</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">创建目录成功</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br></div></div><p><strong>同步版本</strong></p><div class="language-javascript line-numbers-mode"><pre><code><span class="line"><span style="color:#676E95;font-style:italic;">// fs.mkdirSync(path[, mode])</span></span>
<span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> fs </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">require</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fs</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">try</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">fs</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">mkdirSync</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">hello</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">创建目录成功</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#89DDFF;font-style:italic;">catch</span><span style="color:#A6ACCD;">(e)</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#89DDFF;font-style:italic;">throw</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">e</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br></div></div><p><strong>promises</strong></p><div class="language-js line-numbers-mode"><pre><code><span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">mkdir</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fs/promises</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">try</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#C792EA;">const</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">createDir</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">await</span><span style="color:#F07178;"> </span><span style="color:#82AAFF;">mkdir</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">projectFolder</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> recursive</span><span style="color:#89DDFF;">:</span><span style="color:#F07178;"> </span><span style="color:#FF9CAC;">true</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">`</span><span style="color:#C3E88D;">created </span><span style="color:#89DDFF;">${</span><span style="color:#A6ACCD;">createDir</span><span style="color:#89DDFF;">}`</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">catch</span><span style="color:#A6ACCD;"> (err) </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">error</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">err</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">message</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br></div></div><h3 id="_2-6-遍历目录" tabindex="-1">2.6 遍历目录 <a class="header-anchor" href="#_2-6-遍历目录" aria-hidden="true">#</a></h3><p>同步版本，注意：<code>fs.readdirSync()</code>只会读一层，所以需要判断文件类型是否目录，如果是，则进行递归遍历。</p><div class="language-js line-numbers-mode"><pre><code><span class="line"><span style="color:#676E95;font-style:italic;">// fs.readdirSync(path[, options])</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> fs </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">require</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fs</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> path </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">require</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">path</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> getFilesInDir </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">function</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;">dir</span><span style="color:#89DDFF;">){</span></span>
<span class="line"></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#C792EA;">var</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">results</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> [ </span><span style="color:#A6ACCD;">path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">resolve</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">dir</span><span style="color:#F07178;">) ]</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#C792EA;">var</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">files</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">fs</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">readdirSync</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">dir</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">utf8</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">files</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">forEach</span><span style="color:#F07178;">(</span><span style="color:#C792EA;">function</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;">file</span><span style="color:#89DDFF;">){</span></span>
<span class="line"></span>
<span class="line"><span style="color:#F07178;">        </span><span style="color:#A6ACCD;">file</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">path</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">resolve</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">dir</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">file</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#F07178;">        </span><span style="color:#C792EA;">var</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">stats</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">fs</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">statSync</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">file</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#F07178;">        </span><span style="color:#89DDFF;font-style:italic;">if</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">stats</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">isFile</span><span style="color:#F07178;">())</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">            </span><span style="color:#A6ACCD;">results</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">push</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">file</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#F07178;">        </span><span style="color:#89DDFF;">}</span><span style="color:#89DDFF;font-style:italic;">else</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">if</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">stats</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">isDirectory</span><span style="color:#F07178;">())</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">            </span><span style="color:#A6ACCD;">results</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">results</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">concat</span><span style="color:#F07178;">( </span><span style="color:#82AAFF;">getFilesInDir</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">file</span><span style="color:#F07178;">) )</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#F07178;">        </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#89DDFF;">}</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">results</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">};</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> files </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">getFilesInDir</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">../</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">(files)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br><span class="line-number">19</span><br><span class="line-number">20</span><br><span class="line-number">21</span><br><span class="line-number">22</span><br><span class="line-number">23</span><br><span class="line-number">24</span><br><span class="line-number">25</span><br><span class="line-number">26</span><br><span class="line-number">27</span><br><span class="line-number">28</span><br></div></div><h3 id="_2-7-读取目录" tabindex="-1">2.7 读取目录 <a class="header-anchor" href="#_2-7-读取目录" aria-hidden="true">#</a></h3><div class="language-js line-numbers-mode"><pre><code><span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">readdir</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fs/promises</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">try</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#C792EA;">const</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">files</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">await</span><span style="color:#F07178;"> </span><span style="color:#82AAFF;">readdir</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">path</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#89DDFF;font-style:italic;">for</span><span style="color:#F07178;"> (</span><span style="color:#C792EA;">const</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">file</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">of</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">files</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">file</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">catch</span><span style="color:#A6ACCD;"> (err) </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">error</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">err</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br></div></div><h3 id="_2-8-删除目录" tabindex="-1">2.8 删除目录 <a class="header-anchor" href="#_2-8-删除目录" aria-hidden="true">#</a></h3><div class="language-js line-numbers-mode"><pre><code><span class="line"><span style="color:#676E95;font-style:italic;">// 删除目录(前提没有文件在里面)</span></span>
<span class="line"><span style="color:#A6ACCD;">fs</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">rmdir</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./avatar</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> err </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#89DDFF;font-style:italic;">if</span><span style="color:#F07178;"> (</span><span style="color:#A6ACCD;">err</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&amp;&amp;</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">err</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">code</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">===</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">ENOENT</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">) </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">目录不存在</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br></div></div><h3 id="_2-9-删除整个目录" tabindex="-1">2.9 删除整个目录 <a class="header-anchor" href="#_2-9-删除整个目录" aria-hidden="true">#</a></h3><div class="language-js line-numbers-mode"><pre><code><span class="line"><span style="color:#676E95;font-style:italic;">//1</span></span>
<span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> fs </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">require</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&quot;</span><span style="color:#C3E88D;">fs</span><span style="color:#89DDFF;">&quot;</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"><span style="color:#A6ACCD;">fs</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&quot;</span><span style="color:#C3E88D;">./avatar</span><span style="color:#89DDFF;">&quot;</span><span style="color:#89DDFF;">,(</span><span style="color:#A6ACCD;">err</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;">data</span><span style="color:#89DDFF;">)</span><span style="color:#C792EA;">=&gt;</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#89DDFF;">    </span><span style="color:#676E95;font-style:italic;">// console.log(data)</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">data</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">forEach</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">item</span><span style="color:#C792EA;">=&gt;</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">        </span><span style="color:#A6ACCD;">fs</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">unlinkSync</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">`</span><span style="color:#C3E88D;">./avatar/</span><span style="color:#89DDFF;">${</span><span style="color:#A6ACCD;">item</span><span style="color:#89DDFF;">}`</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#89DDFF;">}</span><span style="color:#F07178;">)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">fs</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">rmdir</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&quot;</span><span style="color:#C3E88D;">./avatar</span><span style="color:#89DDFF;">&quot;</span><span style="color:#89DDFF;">,(</span><span style="color:#A6ACCD;">err</span><span style="color:#89DDFF;">)</span><span style="color:#C792EA;">=&gt;</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">        </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">err</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#89DDFF;">}</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#676E95;font-style:italic;">//2</span></span>
<span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> fs </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">require</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fs</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"><span style="color:#A6ACCD;">fs</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">readdir</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&quot;</span><span style="color:#C3E88D;">./avatar</span><span style="color:#89DDFF;">&quot;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">then</span><span style="color:#A6ACCD;">(</span><span style="color:#C792EA;">async</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;">data</span><span style="color:#89DDFF;">)</span><span style="color:#C792EA;">=&gt;</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#C792EA;">let</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">arr</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> []</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">data</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">forEach</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">item</span><span style="color:#C792EA;">=&gt;</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">        </span><span style="color:#A6ACCD;">arr</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">push</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">fs</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">unlink</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">`</span><span style="color:#C3E88D;">./avatar/</span><span style="color:#89DDFF;">${</span><span style="color:#A6ACCD;">item</span><span style="color:#89DDFF;">}`</span><span style="color:#F07178;">))</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#89DDFF;">}</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#89DDFF;font-style:italic;">await</span><span style="color:#F07178;"> </span><span style="color:#FFCB6B;">Promise</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">all</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">arr</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">fs</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">rmdir</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&quot;</span><span style="color:#C3E88D;">./avatar</span><span style="color:#89DDFF;">&quot;</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#676E95;font-style:italic;">//3</span></span>
<span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> fs </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">require</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fs</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">promises</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#A6ACCD;">fs</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">readdir</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./image2</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">then</span><span style="color:#A6ACCD;">(</span><span style="color:#C792EA;">async</span><span style="color:#A6ACCD;"> data </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#89DDFF;font-style:italic;">await</span><span style="color:#F07178;"> </span><span style="color:#FFCB6B;">Promise</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">all</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">data</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">map</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">item</span><span style="color:#F07178;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">fs</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">unlink</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">`</span><span style="color:#C3E88D;">./image2/</span><span style="color:#89DDFF;">${</span><span style="color:#A6ACCD;">item</span><span style="color:#89DDFF;">}`</span><span style="color:#F07178;">)))</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#89DDFF;font-style:italic;">await</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">fs</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">rmdir</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./image2</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br><span class="line-number">19</span><br><span class="line-number">20</span><br><span class="line-number">21</span><br><span class="line-number">22</span><br><span class="line-number">23</span><br><span class="line-number">24</span><br><span class="line-number">25</span><br><span class="line-number">26</span><br><span class="line-number">27</span><br><span class="line-number">28</span><br><span class="line-number">29</span><br><span class="line-number">30</span><br></div></div><h3 id="_2-10-文件重命名" tabindex="-1">2.10 文件重命名 <a class="header-anchor" href="#_2-10-文件重命名" aria-hidden="true">#</a></h3><p><strong>异步版本</strong></p><div class="language-javascript line-numbers-mode"><pre><code><span class="line"><span style="color:#676E95;font-style:italic;">// fs.rename(oldPath, newPath, callback)</span></span>
<span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> fs </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">require</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fs</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#A6ACCD;">fs</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">rename</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./hello</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./world</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">function</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;">err</span><span style="color:#89DDFF;">){</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#89DDFF;font-style:italic;">if</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">err</span><span style="color:#F07178;">) </span><span style="color:#89DDFF;font-style:italic;">throw</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">err</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">重命名成功</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br></div></div><p><strong>同步版本</strong></p><div class="language-js line-numbers-mode"><pre><code><span class="line"><span style="color:#676E95;font-style:italic;">// fs.renameSync(oldPath, newPath)</span></span>
<span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> fs </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">require</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fs</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#A6ACCD;">fs</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">renameSync</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./world</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./hello</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br></div></div><p><strong>promises</strong></p><div class="language-js line-numbers-mode"><pre><code><span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">rename</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fs/promises</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">try</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#89DDFF;font-style:italic;">await</span><span style="color:#F07178;"> </span><span style="color:#82AAFF;">rename</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./world</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./hello</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">`</span><span style="color:#C3E88D;">rename</span><span style="color:#89DDFF;">`</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">catch</span><span style="color:#A6ACCD;"> (err) </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">error</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">err</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">message</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br></div></div><h3 id="_2-11-获取文件状态" tabindex="-1">2.11 获取文件状态 <a class="header-anchor" href="#_2-11-获取文件状态" aria-hidden="true">#</a></h3><p>1.异步：fs.stat(path,callback): path是一个表示路径的字符串,callback接收两个参数(err,stats),其中stats就是fs.stats的一个实例；</p><p>2.同步：fs.statSync(path) 只接收一个path变量，fs.statSync(path)其实是一个fs.stats的一个实例；</p><p>方法</p><ul><li>stats.isFile() -- 是否文件</li><li>stats.isDirectory() -- 是否目录</li></ul><div class="language-js line-numbers-mode"><pre><code><span class="line"><span style="color:#676E95;font-style:italic;">// Node.js program to demonstrate the </span></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// fs.statSync() method </span></span>
<span class="line"><span style="color:#A6ACCD;">  </span></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// Import the filesystem module </span></span>
<span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> fs </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">require</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fs</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span><span style="color:#A6ACCD;"> </span></span>
<span class="line"><span style="color:#A6ACCD;">  </span></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// Getting information for a file </span></span>
<span class="line"><span style="color:#A6ACCD;">statsObj </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> fs</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">statSync</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&quot;</span><span style="color:#C3E88D;">test_file.txt</span><span style="color:#89DDFF;">&quot;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span><span style="color:#A6ACCD;"> </span></span>
<span class="line"><span style="color:#A6ACCD;">  </span></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">(statsObj)</span><span style="color:#89DDFF;">;</span><span style="color:#A6ACCD;">  </span></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&quot;</span><span style="color:#C3E88D;">Path is file:</span><span style="color:#89DDFF;">&quot;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> statsObj</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">isFile</span><span style="color:#A6ACCD;">())</span><span style="color:#89DDFF;">;</span><span style="color:#A6ACCD;"> </span></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&quot;</span><span style="color:#C3E88D;">Path is directory:</span><span style="color:#89DDFF;">&quot;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> statsObj</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">isDirectory</span><span style="color:#A6ACCD;">())</span><span style="color:#89DDFF;">;</span><span style="color:#A6ACCD;"> </span></span>
<span class="line"><span style="color:#A6ACCD;">  </span></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// Getting information for a directory </span></span>
<span class="line"><span style="color:#A6ACCD;">statsObj </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> fs</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">statSync</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&quot;</span><span style="color:#C3E88D;">test_directory</span><span style="color:#89DDFF;">&quot;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span><span style="color:#A6ACCD;"> </span></span>
<span class="line"><span style="color:#A6ACCD;">  </span></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">(statsObj)</span><span style="color:#89DDFF;">;</span><span style="color:#A6ACCD;"> </span></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&quot;</span><span style="color:#C3E88D;">Path is file:</span><span style="color:#89DDFF;">&quot;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> statsObj</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">isFile</span><span style="color:#A6ACCD;">())</span><span style="color:#89DDFF;">;</span><span style="color:#A6ACCD;"> </span></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&quot;</span><span style="color:#C3E88D;">Path is directory:</span><span style="color:#89DDFF;">&quot;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> statsObj</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">isDirectory</span><span style="color:#A6ACCD;">())</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br><span class="line-number">19</span><br></div></div><p>输出：</p><div class="language-js line-numbers-mode"><pre><code><span class="line"><span style="color:#A6ACCD;">Stats </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">dev</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">3229478529</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">mode</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">33206</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">nlink</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">1</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">uid</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">0</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">gid</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">0</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">rdev</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">0</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">blksize</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">4096</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">ino</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">1970324837039946</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">size</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">0</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">blocks</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">0</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">atimeMs</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">1582306776282</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">mtimeMs</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">1582482953967</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">ctimeMs</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">1582482953968.2532</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">birthtimeMs</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">1582306776282.142</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">atime</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">2020</span><span style="color:#89DDFF;">-</span><span style="color:#F78C6C;">02</span><span style="color:#89DDFF;">-</span><span style="color:#F07178;">21</span><span style="color:#FFCB6B;">T17</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">39</span><span style="color:#F07178;">:36</span><span style="color:#89DDFF;">.</span><span style="color:#F07178;">282</span><span style="color:#A6ACCD;">Z</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">mtime</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">2020</span><span style="color:#89DDFF;">-</span><span style="color:#F78C6C;">02</span><span style="color:#89DDFF;">-</span><span style="color:#F07178;">23</span><span style="color:#FFCB6B;">T18</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">35</span><span style="color:#F07178;">:53</span><span style="color:#89DDFF;">.</span><span style="color:#F07178;">967</span><span style="color:#A6ACCD;">Z</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">ctime</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">2020</span><span style="color:#89DDFF;">-</span><span style="color:#F78C6C;">02</span><span style="color:#89DDFF;">-</span><span style="color:#F07178;">23</span><span style="color:#FFCB6B;">T18</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">35</span><span style="color:#F07178;">:53</span><span style="color:#89DDFF;">.</span><span style="color:#F07178;">968</span><span style="color:#A6ACCD;">Z</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">birthtime</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">2020</span><span style="color:#89DDFF;">-</span><span style="color:#F78C6C;">02</span><span style="color:#89DDFF;">-</span><span style="color:#F07178;">21</span><span style="color:#FFCB6B;">T17</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">39</span><span style="color:#F07178;">:36</span><span style="color:#89DDFF;">.</span><span style="color:#F07178;">282</span><span style="color:#A6ACCD;">Z</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#A6ACCD;">Path is </span><span style="color:#FFCB6B;">file</span><span style="color:#89DDFF;">:</span><span style="color:#FF9CAC;">true</span></span>
<span class="line"><span style="color:#A6ACCD;">Path is </span><span style="color:#FFCB6B;">directory</span><span style="color:#89DDFF;">:</span><span style="color:#FF9CAC;">false</span></span>
<span class="line"><span style="color:#A6ACCD;">Stats </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">dev</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">3229478529</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">mode</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">16822</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">nlink</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">1</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">uid</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">0</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">gid</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">0</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">rdev</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">0</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">blksize</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">4096</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">ino</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">562949953486669</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">size</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">0</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">blocks</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">0</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">atimeMs</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">1582482965037.8445</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">mtimeMs</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">1581074249467.7114</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">ctimeMs</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">1582482964979.8303</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">birthtimeMs</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">1582306776288.1958</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">atime</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">2020</span><span style="color:#89DDFF;">-</span><span style="color:#F78C6C;">02</span><span style="color:#89DDFF;">-</span><span style="color:#F07178;">23</span><span style="color:#FFCB6B;">T18</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">36</span><span style="color:#F07178;">:</span><span style="color:#F78C6C;">05</span><span style="color:#89DDFF;">.</span><span style="color:#F07178;">038</span><span style="color:#A6ACCD;">Z</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">mtime</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">2020</span><span style="color:#89DDFF;">-</span><span style="color:#F78C6C;">02</span><span style="color:#89DDFF;">-</span><span style="color:#F07178;">07</span><span style="color:#FFCB6B;">T11</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">17</span><span style="color:#F07178;">:29</span><span style="color:#89DDFF;">.</span><span style="color:#F07178;">468</span><span style="color:#A6ACCD;">Z</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">ctime</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">2020</span><span style="color:#89DDFF;">-</span><span style="color:#F78C6C;">02</span><span style="color:#89DDFF;">-</span><span style="color:#F07178;">23</span><span style="color:#FFCB6B;">T18</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">36</span><span style="color:#F07178;">:</span><span style="color:#F78C6C;">04</span><span style="color:#89DDFF;">.</span><span style="color:#F07178;">980</span><span style="color:#A6ACCD;">Z</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;">  </span><span style="color:#FFCB6B;">birthtime</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">2020</span><span style="color:#89DDFF;">-</span><span style="color:#F78C6C;">02</span><span style="color:#89DDFF;">-</span><span style="color:#F07178;">21</span><span style="color:#FFCB6B;">T17</span><span style="color:#89DDFF;">:</span><span style="color:#F78C6C;">39</span><span style="color:#F07178;">:36</span><span style="color:#89DDFF;">.</span><span style="color:#F07178;">288</span><span style="color:#A6ACCD;">Z</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#A6ACCD;">Path is </span><span style="color:#FFCB6B;">file</span><span style="color:#89DDFF;">:</span><span style="color:#FF9CAC;">false</span></span>
<span class="line"><span style="color:#A6ACCD;">Path is </span><span style="color:#FFCB6B;">directory</span><span style="color:#89DDFF;">:</span><span style="color:#FF9CAC;">true</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br><span class="line-number">19</span><br><span class="line-number">20</span><br><span class="line-number">21</span><br><span class="line-number">22</span><br><span class="line-number">23</span><br><span class="line-number">24</span><br><span class="line-number">25</span><br><span class="line-number">26</span><br><span class="line-number">27</span><br><span class="line-number">28</span><br><span class="line-number">29</span><br><span class="line-number">30</span><br><span class="line-number">31</span><br><span class="line-number">32</span><br><span class="line-number">33</span><br><span class="line-number">34</span><br><span class="line-number">35</span><br><span class="line-number">36</span><br><span class="line-number">37</span><br><span class="line-number">38</span><br><span class="line-number">39</span><br><span class="line-number">40</span><br><span class="line-number">41</span><br><span class="line-number">42</span><br><span class="line-number">43</span><br><span class="line-number">44</span><br></div></div><h3 id="_2-12-追加文件内容" tabindex="-1">2.12 追加文件内容 <a class="header-anchor" href="#_2-12-追加文件内容" aria-hidden="true">#</a></h3><blockquote><p>fs.appendFile(file, data[, options], callback)</p></blockquote><ul><li>file：可以是文件路径，也可以是文件句柄。（还可以是buffer？）</li><li>data：要追加的内容。string或者buffer。</li><li>options <ul><li>encoding：编码，默认是<code>utf8</code></li><li>mode：默认是<code>0o666</code></li><li>flag：默认是<code>a</code></li></ul></li></ul><p>注意：如果<code>file</code>是文件句柄，那么</p><ul><li>开始追加数据前，file需要已经打开。</li><li>file需要手动关闭。</li></ul><div class="language-javascript line-numbers-mode"><pre><code><span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> fs </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">require</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fs</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#A6ACCD;">fs</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">appendFile</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./extra/fileForAppend.txt</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">hello</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">utf8</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">function</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;">err</span><span style="color:#89DDFF;">){</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#89DDFF;font-style:italic;">if</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">err</span><span style="color:#F07178;">) </span><span style="color:#89DDFF;font-style:italic;">throw</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">err</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">append成功</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br></div></div><h2 id="_3-事件机制模块-events" tabindex="-1">3.事件机制模块 events <a class="header-anchor" href="#_3-事件机制模块-events" aria-hidden="true">#</a></h2><p>Node.js 有多个内置的事件，我们可以通过引入 events 模块，并通过实例化 EventEmitter 类来绑定和监听事件，如下实例：</p><div class="language-javascript line-numbers-mode"><pre><code><span class="line"><span style="color:#676E95;font-style:italic;">// 引入 events 模块</span></span>
<span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> EventEmitter </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">require</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">events</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// 创建 eventEmitter 对象</span></span>
<span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> event </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">new</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">EventEmitter</span><span style="color:#A6ACCD;">()</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br></div></div><p>以下程序绑定事件处理程序：</p><div class="language-javascript line-numbers-mode"><pre><code><span class="line"><span style="color:#676E95;font-style:italic;">// 绑定事件及事件的处理程序</span></span>
<span class="line"><span style="color:#A6ACCD;">eventEmitter</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">on</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">eventName</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> eventHandler)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br></div></div><p>我们可以通过程序触发事件：</p><div class="language-javascript line-numbers-mode"><pre><code><span class="line"><span style="color:#676E95;font-style:italic;">// 触发事件</span></span>
<span class="line"><span style="color:#A6ACCD;">eventEmitter</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">emit</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">eventName</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br></div></div><p><code>EventEmitter </code>的每个事件由一个事件名和若干个参数组成，事件名是一个字符串，通常表达一定的语义。对于每个事件，<code>EventEmitter </code>支持 若干个事件监听器。</p><p>当事件触发时，注册到这个事件的事件监听器被依次调用，事件参数作为回调函数参数传递。</p><p>让我们以下面的例子解释这个过程：</p><div class="language-javascript line-numbers-mode"><pre><code><span class="line"><span style="color:#676E95;font-style:italic;">// 引入 events 模块</span></span>
<span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> EventEmitter </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">require</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">events</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// 创建 eventEmitter 对象</span></span>
<span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> event </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">new</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">EventEmitter</span><span style="color:#A6ACCD;">()</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#A6ACCD;">event</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">on</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">someEvent</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">function</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;">arg1</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> arg2</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">listener1</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">arg1</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">arg2</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span><span style="color:#F07178;"> </span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span><span style="color:#A6ACCD;"> </span></span>
<span class="line"><span style="color:#A6ACCD;">event</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">on</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">someEvent</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">function</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;">arg1</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> arg2</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">listener2</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">arg1</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">arg2</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span><span style="color:#F07178;"> </span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span><span style="color:#A6ACCD;"> </span></span>
<span class="line"><span style="color:#A6ACCD;">event</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">emit</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">someEvent</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">arg1 参数</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">arg2 参数</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span><span style="color:#A6ACCD;"> </span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br></div></div><p>执行以上代码，运行的结果如下：</p><div class="language-bash line-numbers-mode"><pre><code><span class="line"><span style="color:#A6ACCD;">$ node event.js </span></span>
<span class="line"><span style="color:#A6ACCD;">listener1 arg1 参数 arg2 参数</span></span>
<span class="line"><span style="color:#A6ACCD;">listener2 arg1 参数 arg2 参数</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br></div></div><p>以上例子中，event 为事件 someEvent 注册了两个事件监听器，然后触发了 someEvent 事件。</p><p>运行结果中可以看到两个事件监听器回调函数被先后调用。 这就是<code>EventEmitter</code>最简单的用法。</p><p><code>EventEmitter </code>提供了多个属性，如 <strong>on</strong> 和 <strong>emit</strong>。<strong>on</strong> 函数用于绑定事件函数，<strong>emit</strong> 属性用于触发一个事件</p></div></div><!----></main><!--[--><!--]--><footer class="VPContentDocFooter" data-v-4fe9b7bd data-v-7f892bef><a class="prev-link" href="/nodejs/05.html" data-v-7f892bef><span class="desc" data-v-7f892bef><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" viewbox="0 0 24 24" class="vt-link-icon" data-v-7f892bef><path d="M15,19c-0.3,0-0.5-0.1-0.7-0.3l-6-6c-0.4-0.4-0.4-1,0-1.4l6-6c0.4-0.4,1-0.4,1.4,0s0.4,1,0,1.4L10.4,12l5.3,5.3c0.4,0.4,0.4,1,0,1.4C15.5,18.9,15.3,19,15,19z"></path></svg> Previous</span><span class="title" data-v-7f892bef>05 【nodejs内置模块（上）】</span></a><a class="next-link" href="/nodejs/07.html" data-v-7f892bef><span class="desc" data-v-7f892bef>Next <svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" viewbox="0 0 24 24" class="vt-link-icon" data-v-7f892bef><path d="M9,19c-0.3,0-0.5-0.1-0.7-0.3c-0.4-0.4-0.4-1,0-1.4l5.3-5.3L8.3,6.7c-0.4-0.4-0.4-1,0-1.4s1-0.4,1.4,0l6,6c0.4,0.4,0.4,1,0,1.4l-6,6C9.5,18.9,9.3,19,9,19z"></path></svg></span><span class="title" data-v-7f892bef>07 【nodejs内置模块（下）】</span></a></footer></div></div></div></div><div class="visually-hidden" aria-live="polite" data-v-23306c50>06 【nodejs内置模块（中）】 has loaded</div></div></div>
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